This invention relates to the packaging of electrical storage battery cell-packs, and more particularly to a process for adapting a universal battery case to use with a variety of cell-pack sizes.
Automobile battery containers have standardized outside dimensions and battery manufacturers provide different energy capacity batteries in each case size. This is done by varying the number of positive and negative plates in each cell which in turn varies the thickness of the cell pack comprising those plates. Traditionally the lower energy batteries contain about nine plates per cell-pack while the higher energy batteries contain about sixteen plates per cell-pack, and these packs vary in thickness from about 2.42 cms. to about 4.24 cms., respectively. Each cell-pack is spaced from the walls of the cell compartment and held substantially centrally of the compartment by ribs molded onto the compartment walls. Larger ribs (i.e., in greater relief from their associated wall) are used for the thinner packs and conversely smaller ribs for the thicker packs. To provide this variety of batteries, many battery manufacturers inventory at least one case mold for each battery model it sells and consume time and effort in changing over from one mold to the next for each production run. Other manufacturers inventory a lesser number of molds and incorporate inert spacers (e.g., extra separators, corrugated plastic sheets, etc.) in each cell pack to effect a standardized cell pack thickness regardless of the number of electrochemically active plates in each pack. This approach however, adds the cost of the spacers to the battery and frequently complicates the in-plant handling of the cell pack, particularly during its insertion into the case.
It is an object of this invention to provide a battery case rib trimming operation and tool which are consistently reliable under high speed mechanized production conditions, and as a result, achieve substantial economies from the use of a single universal case (i.e., container) for several battery models in each standardized size, which case is molded with spacer ribs sized for use with the narrowest cell pack useful with the case, which ribs are thereafter accurately trimmed off at a predetermined distance from the cell compartment walls to accommodate thicker cell packs. This and other objects and advantages of the invention will become more apparent from the detailed description which follows.